The fullest and most systematic treatment of the ideas on church unity advocated by King James was written by an Italian, Marco Antonio De Dominis, formerly the Roman Catholic archbishop of Spalato. De Dominis's De republica ecclesiastica, published in Latin between 1617 and 1622 in three stout folio volumes, reached a European-wide audience. Its impact was blunted, however, because De Dominis's “shirtings in religion” caused him, by the time of his death in 1624, to be regarded as an apostate by both Roman Catholics and Protestants. De Dominis arrived in England on December 6, 1616 from Venice, after two and a half months of travel across northern Italy, Switzerland, the Rhineland, and the Netherlands. He had left Italy disguised as a Ragusan merchant, and had been joined on his journey by Robert Barnes and David Murray, two of King James's subjects. According to the historian Arthur Wilson, De Dominis was “old and corpulent, unfit for Travel, being almost at his journies end by Nature”; yet he began to speak out vigorously against the faith and practices of the Church of Rome soon after his arrival in England. Warmly welcomed by George Abbot, the archbishop of Canterbury, and by the king, De Dominis was given several appointments in the Church of England – including that of dean of the Chapel Royal at Windsor and master of the Savoy in London – and became a prominent anti-Roman Catholic controversialist, as well as a spokesman for a reorganized and more inclusive universal Church.